Purification of Euglena gracilis chloroplast elongation factor Ts

Previous studies have demonstrated that the activity of Euglena gracilis chloroplast elongation factor Ts is regulated by light and the gene for this factor is nuclear coded (Fox, L., Erion, J., Tarnowski, J., Spremulli, L., Brot, N., and Weissbach, H., J. Biol. Chem. (1980) 255, 6018-6019). Chloroplast elongation factor Ts has been purified to near homogeneity from E. gracilis extracts prepared from light-grown cells. It is composed of a single polypeptide chain of approximately 62,000 daltons. It interacts stoichiometrically with Escherichia coli elongation factor Tu to form an elongation factor Tu.elongation factor Ts complex.